A Proper Kohen

The chassidic mentor in Tomchei Temim, Reb Shmuel Gronem Estherman, once recalled the following story:

It was the Alter Rebbe, Rabbi Shneur Zalman of Liadi’s custom to read the Torah be the one to call people to the Torah.

Once, the Rebbe called a certain chossid for the Kohen aliya, who, until that point did not consider himself a Kohen. However, from that point on this chossid considered himself a proper Kohen, as the Rebbe himself had declared that he was.

(Reshimos Devarim, Vol 1 Pg. 66)